1. Field of the Invention:
This invention relates to disc recording and transcribing apparatus and more specifically to apparatus for accurately placing the soundhead in a disc dictation machine at a predetermined position.
2. Description of the Prior Art:
U.S. Pat. No. 3,789,160 entitled "Dictation Apparatus With Disc Loading, Feeding and Ejecting Feature", issued to J. D. Bruer, et al., Jan. 29, 1974 and assigned to the same assignee as the present invention, discloses a disc dictation system featuring automated loading, feeding and unloading operations wherein the soundhead is restored to its starting position during a disc change cycle through the interaction of the soundhead transport mechanism with the disc change loader carrier mechanism. In this prior art patent, the loader carrier moves from a home position to a load/eject position to load a new disc into the record/playback station of the dictation machine. As the loader carrier returns to the home position, it interacts with the soundhead transport to restore the soundhead to its starting position. In this arrangement, the soundhead reaches its start position before the loader carrier reaches its home position and the soundhead is disengaged from the loader carrier while the loader carrier is still in motion.
In this prior art soundhead restore mechanism, accurate positioning of the soundhead at its start phasing position could not be guaranteed because the soundhead was subject to bounce when released at the loader carrier returning speed of approximately 25 inches per second. Also, this soundhead restore mechanism engaged the loader carrier as it started to accelerate toward the home position and was at a mechanical disadvantage because the loader carrier was not at full speed. This caused the changer to intermittently stall.